Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: chocopower on August 11, 2023, 11:01:43 am

Title: Ekosonic amp
Post by: chocopower on August 11, 2023, 11:01:43 am

Hi


Got this one from a friend.


P.T. is not original, and seems some inner stuff had been changed too.
Schematic in progress, but basically is a 12ax7 front with a EL84  output and a 6AT6 for tremolo.
EZ81 for rectifier.


I think is an 60s italian amplifier made by EKO (still in business)


If somebody have an schematic will be great.
Title: Re: Ekosonic amp
Post by: Latole on August 11, 2023, 01:11:28 pm
Good luck to find schematic

One Ekosonic I found :

Ekosonic 120 S ;https://schematichell.com/ekosonic/
Title: Re: Ekosonic amp
Post by: chocopower on August 11, 2023, 03:31:02 pm
Amp is quite simple. Maybe i struggle with the tremolo, just because is something I'm not used to, but besides that shouldn't be a problem.


Right now, my main concern is a .047 cap with one side attached to ground and the other just hanging in the air.
The ground side is in one dummy pin in the EL84.
The loose side, "seems" to me, that was connected to the EL84 plate, but couldn't say....
Title: Re: Ekosonic amp
Post by: tubeswell on August 11, 2023, 04:31:47 pm
If it’s a simple circuit, it shouldn’t be too difficult to re-engineer a schematic with a pencil, rubber and a piece of paper. If you post a series of gut shots from different angles, so that we can all see everything, people here might be able to help with the exercise in retrieving historical information
Title: Re: Ekosonic amp
Post by: kagliostro on August 11, 2023, 05:06:49 pm
The link posted by Latole (Ciao Latole) show a schematic with an odd part, the triode of the 12au7 tube that is near the power tube has a pair of odd connections (labeled Z)


Franco
Title: Re: Ekosonic amp
Post by: Latole on August 12, 2023, 04:28:31 am
Quote from: tubeswell on August 11, 2023, 04:31:47 pm
If it’s a simple circuit, it shouldn’t be too difficult to re-engineer a schematic with a pencil, rubber and a piece of paper. If you post a series of gut shots from different angles, so that we can all see everything, people here might be able to help with the exercise in retrieving historical information

Right !
Title: Re: Ekosonic amp
Post by: kagliostro on August 13, 2023, 06:04:12 pm
The schematic previously posted was the 120S, I've find a 120 schematic

It didn't seem to be your amp, however as they are really rare I post it

I've find this

(https://i.imgur.com/fZr2x3X.jpg)

and after a bit of work arrived to this

(https://i.imgur.com/aNDsxne.jpg)

Franco

Title: Re: Ekosonic amp
Post by: tubeswell on August 13, 2023, 08:07:00 pm
Quote from: kagliostro on August 13, 2023, 06:04:12 pm
and after a bit of work arrived to this


Nice work